The present invention relates to an image forming apparatus and, in particular, to an image forming apparatus capable of preventing that the rear part of a recording medium in the conveying direction contacts with a nozzle surface of a recording head.
A line type printer comprises mainly: an endless conveyance belt for conveying a recording medium; a driven roller and a driving roller around which a conveyance belt is wound; and driving means for driving the driving roller. Then, a driving force generated by the driving means is transmitted to the conveyance belt via the driving roller so that the recording medium is conveyed by the conveyance belt. At the same time, ink is ejected from a recording head so that a desired image is formed on the recording medium.
In this line type printer, recording mediums can successively be fed from a paper feed unit onto the conveyance belt so that high-speed printing is achieved. Nevertheless, in order that accuracy should be ensured in the ink impact, the gap need be remarkably small between the recording head and the recording medium. This has caused a problem that when the conveyance belt rotates at high speed, vibrations in the conveyance belt generates fluctuation in the gap between the recording medium and the recording head, and thereby degrades the image quality.
In contrast, Japanese Patent Application Laid-Open No. 2-86475 (1990) discloses a technique in which a support member for causing a belt (conveyance belt) portion opposing the recording head to be supported on the opposite side of the recording head is provided on the inner periphery surface side of the belt. According to this technique, even when the belt rotates at high speed, vibrations in the belt are suppressed by the support member so that the generation of said gap fluctuation is suppressed.